I. Field of the Invention
The present invention relates generally to the field of labeling and to in-line printing and converting processes. The present invention relates specifically to a single-pass, in-line process for (i) constructing multi-ply resealable labels that accommodate intermediate plies smaller in size than the overall label dimensions, and (ii) manufacturing discrete elements combined with primary substrates, such as film-covered windows within carton materials.
II. Background of the Invention
Multi-ply labels, variously referred to as “multi-layered ”, “extended text”, “expanded content” or “booklet” labels, carry text on a plurality of surfaces and are useful for consumer products, particularly those sold in bottles, cans, cartons, and tubes, where it is desirable to present additional information to the consumer which cannot conveniently be contained on a single printed label surface. Particularly in view of the increasing amount of governmental regulation and labeling requirements, many consumer products contained in such packaging must carry additional information including detailed instructions for use, detailed listings of the contents, a variety of consumer product warnings, and provisions for multi-lingual information.
Multi-ply labels normally contain two or more layers or plies of label material hinged together adhesively along one margin, and close utilizing a pressure sensitive release-reseal system along the opposite margin. It is often desirable that one or more internal, middle or intermediate plies be added between an upper or top ply and a bottom or base ply. It is further advantageous if the intermediate plies can be hinged between the top ply and base plies yet not interfere with or be required to be part of a release-reseal closure system involving top and base plies. This can be accomplished by making internal or intermediate plies shorter than the top and base plies so that the free ends of the intermediate plies do not extend into the release-reseal margin area. In this way, intermediate plies are hinged like the pages of a book when a label is open, yet are confined within a resealed or closed label.
While the above is a desirable configuration or label construction for labels of a class having three or more plies, automation of an in-line, single pass process to mass produce such labels has been thwarted. One problem arises because the slightly smaller intermediate ply or plies must be sized separately and prior to any final sizing cut for the assembled labels. This problem, among others, has heretofore proved to be an impediment to mass production in-line, single pass automation.
One in-line process for multi-ply labels is illustrated and described in U.S. Patent Application Publication US 2002/0084026 A1 to Matthews et al., teaching the use of a pressure-sensitive adhesive overlaminate to hold two webs together. That in-line construction, however, results in a costly and unnecessarily complex multiple layer label.
Thus, it would present a distinct advantage if the process for making hinged multi-ply labels could be simplified and automated, particularly for those multi-ply labels designed to have one or more under-sized intermediate plies configured in resealable booklet-label form.
Additionally, in-line, continuous web processes are well known in the art for accurate, high volume production of cartons and other printed matter. Such in-line web processes, relative to earlier printing and converting techniques, have offered superior print-to-print and print-to-die registration, and other desirable effects. Heretofore, however, known in-line processes have been unable to provide for the manufacturing of items which feature discrete elements combined with primary substrates, such as film-covered windows with a carton material.
So-called “pick-and-place” methods have, therefore, been typically used for these constructions. In a pick-and-place operation, discrete elements are cut to size off-line and supplied separately, in a magazine, to a printing and converting press or to packaging equipment. The discrete elements would then be sequentially ejected from the magazine and adhered onto a passing base web as known to those in the art. As also known to those in the art, analogous to the pick-and place equipment, relative to film for carton windows, is off-line “windowing” equipment. Pick-and-place methods along with windowing equipment, however, suffer several drawbacks. Chief among these is a failure to maintain proper registration or holding of tolerances between items being combined. Such operations are also relatively slow as compared to true in-line processes, because of a need for rather precise placement of the separately created discrete elements on the passing base web. Further, reliability of discrete element placement is subject to mechanical problems that may arise in the equipment, and to inadvertently empty supply magazines.
Therefore, there also exists a need for a single-pass, in-line process for manufacturing discrete elements combined with primary substrates, which overcomes the significant drawbacks of known pick-and-place, windowing, and similar techniques.